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Biomedical subjects

B M Buckley

Publications and source records attributed to B M Buckley.

At least 37 records · Page 2Linked to original sources
PubMed1987

Lack of evidence of low ionized calcium levels in systemic hypertension.

An epidemiologic screening survey was conducted in 325 male industrial workers to investigate the relation between serum total and ionized calcium concentrations and blood pressure. No relation was found. Previous reports of lower serum ionized calcium levels in hypertensive patients may be related to methodologic deficiencies both in the selection of subjects and in ionized calcium measurement. These data do not support the concept that increased blood pressure levels are related to calcium deficiency or to abnormal plasma calcium homeostasis.

Adult↗
PubMed1987

Drugs as probes of organ function: evaluation of the hepatobiliary axis using oral rifampicin and novel high performance liquid chromatography.

Investigation of the uptake and metabolism of drugs by organs such as the liver may allow assessment of specific aspects of organ function. Rifampicin, when orally administered, is transported into the hepatocyte from portal blood and thence passes, with its deacetylated metabolite, into the systemic circulation and into bile. This paper reports an investigation of the pharmacokinetics of a sub-therapeutic oral dose of rifampicin in healthy subjects, in patients with cirrhosis and in subjects with Gilbert's syndrome. The areas under the plasma concentration curves (AUC) in patients with cirrhosis were significantly greater than in healthy subjects. Subjects with Gilbert's syndrome had decreased AUCs compared with healthy subjects and were clearly distinguished from patients with cirrhosis. Rifampicin concentration in serum was measured by HPLC using a novel direct injection technique.

Acetylation↗
PubMed1987

Measurement of ethylene glycol (ethane-1,2-diol) in biological specimens using derivatisation and gas-liquid chromatography with flame ionisation detection.

Ethylene glycol in plasma, urine or dialysis fluid is analysed as the phenylboronate derivative by mixing with acetonitrile/acidified 2,2-dimethoxypropane containing phenylboronic acid. After centrifugation, a portion of the supernatant is analysed directly by gas-liquid chromatography using a 3% OV-101 column at 150 degrees C and flame-ionisation detection. Propane-1,3-diol is used as a reactive internal standard. The limit of accurate measurement is at least 0.1 g/L and the linear range extends up to 5.0 g/L. No sources of interference have been identified.

Adult↗
PubMed1987

Rapid measurement of anticonvulsant drug concentrations in the out-patient clinic, using HPLC with direct injection of plasma.

A manual column-switching technique is described for the measurement of phenytoin, phenobarbitone, carbamazepine, and carbamazepine 10,11-epoxide. The analytical system is designed to be portable for use at the out-patient clinic and comprises an isocratic pump, UV detector and injection valve, together with a preparation column. Diluted plasma or serum is injected, without pre-extraction, onto a preparation column which replaces the sample loop on the injection valve. After washing unwanted material to waste, the preparation column is switched in-line with the analytical column, where separation of analytes occurs. The precision, accuracy and carryover of this extra-laboratory system are comparable with those obtained with laboratory-based immunoassay systems. Operation of the system allows the reporting of results within 5 min of sample injection and requires no specialist skills. The technique should be of particular interest to district general hospital laboratories where workload does not justify the cost of an automated HPLC system as the total capital cost is comparable to that of a portable glucose analyser. In contrast to immunoassay systems consumable costs are minimal. The equipment is easy to transport and may be used in the out-patient department to provide an analytical service similar to that provided for the determination of prothrombin time at the anticoagulant clinic.

Carbamazepine↗
PubMed1987

Paraquat poisoning: clinical features and immediate general management.

In contrast to 10-15 years ago most cases of paraquat poisoning are now due to deliberate self-poisoning with parasuicidal or suicidal intent rather than to accidental ingestion. Less commonly, poisoning may follow careless handling of paraquat during occupational use. Although paraquat can be absorbed through the skin if improperly handled, poisoning usually follows ingestion and has rarely been reported after subcutaneous, intravenous or intraperitoneal injection. Clinically, three degrees of intoxication may be distinguished. Mild poisoning occurs after the ingestion or injection of less than 20 mg of paraquat ion/kg body weight. In these cases patients are either asymptomatic or symptoms are confined to the gastrointestinal system. All patients recover fully. Moderate to severe poisoning usually follows the ingestion (rarely injection) of 20-40 mg of paraquat ion/kg body weight. Non-specific symptoms of ill health together with local gastrointestinal symptoms precede the development of renal failure (which may recover spontaneously) and pulmonary fibrosis which may not be manifest for days or weeks. Death occurs in the majority of cases but is usually delayed for 2-3 weeks. Acute fulminant poisoning follows the ingestion of substantial quantities of paraquat (greater than 40 mg of paraquat ion/kg body weight). In addition to local symptoms, multiple organ (cardiac, respiratory, hepatic, renal, adrenal, pancreatic, neurological) failure occurs. Death may supervene within hours and is never delayed for more than a few days. Initial general management has four priorities.(ABSTRACT TRUNCATED AT 250 WORDS)

Humans↗
PubMed1987

Acute pesticide poisoning in England and Wales.

Between 1979 and 1983 less than 1% of admissions from acute poisoning in the UK were due to pesticides and fewer than 4% of admissions in those under 5 years were from this cause. Organochlorine, organophosphorus and carbamate insecticides account for only 10% of the total in both children and adults. Suspected pesticide poisoning was the cause of fewer than 0.3% of home accidents in those under 10 years of age and less than 4% of suspected poisonings documented by the Home Accident Surveillance System. Rodenticides were thought to be involved in 62% of these cases. Of children who presented to hospital 42% were admitted and 93% of these were discharged home within 2 days. In the UK, the morbidity from acute pesticide poisoning in children is low and the mortality is nil and there is therefore no evidence to support the view that paediatric pesticide intoxication is a significant clinical problem. Though no fatalities were recorded in children, pesticides were responsible for 1.3% of all deaths due to poisoning in the UK between 1979 and 1983. In adults admitted to hospital, the mortality from pesticide poisoning is approximately 12% and three quarters of these deaths are due to the deliberate ingestion of paraquat. The general term pesticide refers to a group of products that are used as insecticides, acaricides, fungicides, herbicides, rodenticides, and plant growth agents. Chemically, the group includes bipyridilium compounds, carbamates, chloralose, chlorates, coumarins, dinitro compounds, dithiocarbamates, fluoroacetates, organochlorine organophosphorus and organotin compounds, pentachlorophenol, phenoxyacetates, phosphine (as magnesium and aluminium phosphides), pyrethrins, pyrethroids and triazines.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1987

Hyperlactataemia and metabolic acidosis following paracetamol overdose.

Plasma lactate concentrations and acid-base status were determined in 53 patients poisoned with paracetamol. Eleven patients (Group 1) had plasma paracetamol concentrations below the standard treatment decision line; 19 cases (Group 2) presenting within 15 h of overdose had plasma paracetamol concentrations above the treatment line and received N-acetylcysteine. The remaining 23 patients (Group 3) arrived at hospital too late (more than 15 h after overdose) for treatment with N-acetylcysteine to be completely effective. Compensated metabolic acidosis was present on admission in 55 per cent of Group 1 and 42 per cent of Group 2 patients, and a further 21 per cent of cases in Group 2 had an uncompensated metabolic acidosis. Half the patients in Group 3 were acidotic: 22 per cent had a compensated and 26 per cent an uncompensated metabolic acidosis. On admission, the mean plasma lactate concentration was elevated in both Group 2 and Group 3 patients though not in Group 1 cases. Plasma lactate concentration then fell to normal in patients in Group 2 but became mildly elevated again in some cases at a time which coincided closely with the peak in serum aspartate aminotransferase activity. In patients presenting within 15 h of overdose there was a significant correlation between the elevation in plasma concentrations of lactate and paracetamol at admission. In patients presenting late (Group 3), plasma lactate remained elevated for longer than in Group 2 and acidosis and hyperlactataemia were prominent features in the four patients who died. This study demonstrates first that hyperlactataemia, with or without significant acid-base disturbance, is common following paracetamol overdose particularly in those who are severely poisoned. As uncompensated metabolic acidosis is found in 20 per cent of patients who present early and require protective therapy, it should be sought and corrected if it does not remit spontaneously. Second, half the patients presenting too late for effective treatment are acidotic and those with an uncompensated metabolic acidosis resistant to correction have a poor prognosis. Paracetamol poisoning should be considered in the differential diagnosis of metabolic acidosis of unknown aetiology.

Acetaminophen↗
PubMed1987

Performance requirements of tests performed nearer the patient.

Commercial test systems which can be used outside the laboratory are proliferating, but there are doubts about the quality of results obtained when they are used by unskilled staff. Although rapid but approximate results can be invaluable in some clinical situations, they can be disastrous in others, particularly when the results conflict with those obtained by conventional laboratory techniques. The clinician needs to define his requirements for the quality of such tests, and the manufacturer encouraged to produce equipment which gives accurate results, independent of the skill of the operator. The laboratory scientist has an important role in the development and effective application of tests performed nearer the patient.

Clinical Laboratory Techniques↗
PubMed1986

Paraquat poisoning.

Explore the source record for details and available documents.

Combined Modality Therapy↗
PubMed1986

Plasma ionized calcium monitoring during liver transplantation.

Plasma ionized calcium and citrate concentrations were measured in 11 patients undergoing liver transplantation. During the anhepatic phase of the procedure, ionized calcium concentrations fell to as low as 40% of normal, in spite of calcium supplementation. Simultaneously, citrate concentrations rose to between 20 and 100 times preoperative levels. In two patients low plasma ionized calcium concentrations were associated with hypotension that responded to calcium infusion. Intraoperative monitoring of plasma ionized calcium during liver transplantation is helpful in the rational control of the patient's calcium status.

Calcium↗
PubMed1986

Exocrine pancreatic function as determined in a same-day test with use of bentiromide and p-aminosalicylic acid.

We describe a new approach to the bentiromide test of exocrine pancreatic function, p-Aminosalicylic acid (PAS), a compound closely related to the bentiromide fragment p-aminobenzoic acid (PABA), is used as a marker of the pharmacokinetic behavior of PABA to derive a PABA excretion index. This index is identical to that derived with [14C]-PABA. Concentrations of both PABA and PAS are measured in urine by "high-performance" liquid chromatography, which avoids the drug interferences encountered with established assays of PABA. We discuss the practical and diagnostic advantages of this new approach to the bentiromide test.

4-Aminobenzoic Acid↗